Differential gait kinematics between fallers and non-fallers in community-dwelling elderly people

Females Present Reduced Minimum Toe Clearance During Walking As Compared to Males in Active Older Adults

BACKGROUND

Physical decline due to aging has been associated with the risk of falls. Minimum toe clearance (MTC) is a gait parameter that might play a role in the mechanism of tripping and falling. However, it is unclear if there are any sex-related effects regarding MTC as people age. The present study investigated if there are sex-related differences in MTC in older active adults.

METHODS

Twenty-three females and 23 males (F: 65.5 ± 4.8 years; M: 61.9 ± 5.2 years) walked on a treadmill at a preferred walking speed, while kinematic data were obtained at a sampling frequency of 100 Hz and up-sampled to 120 and 240 Hz. MTC was calculated from the kinematics data and evaluated concerning its magnitude (ie, MTC and MTC/leg length), the time between left/right MTC (ie, T-MTC), amount of variability (ie, coefficient of variation [CV] and coefficient of variation modified [CVm]), and temporal structure of variability, that is, the complexity of the time series (ie, MTC α, T-MTC α).

RESULTS

No sex effects were found for MTC/leg length, for the amount of variability (ie, CV and CVm), and for the complexity of the time series (MTC α, T-MTC α). However, females exhibited significantly lower MTC and T-MTC after adjusting for walking speed, mass, and age as covariates.

CONCLUSIONS

The reduced MTC in females suggests a potential sex-related disparity in the risk of tripping and falling among active older adults.

The Difference in the Assessment of Knee Extension/Flexion Angles during Gait between Two Calibration Methods for Wearable Goniometer Sensors

Frontal and axial knee motion can affect the accuracy of the knee extension/flexion motion measurement using a wearable goniometer. The purpose of this study was to test the hypothesis that calibrating the goniometer on an individual's body would reduce errors in knee flexion angle during gait, compared to bench calibration. Ten young adults (23.2 ± 1.3 years) were enrolled. Knee flexion angles during gait were simultaneously assessed using a wearable goniometer sensor and an optical three-dimensional motion analysis system, and the absolute error (AE) between the two methods was calculated. The mean AE across a gait cycle was 2.4° (0.5°) for the on-body calibration, and the AE was acceptable (<5°) throughout a gait cycle (range: 1.5-3.8°). The mean AE for the on-bench calibration was 4.9° (3.4°) (range: 1.9-13.6°). Statistical parametric mapping (SPM) analysis revealed that the AE of the on-body calibration was significantly smaller than that of the on-bench calibration during 67-82% of the gait cycle. The results indicated that the on-body calibration of a goniometer sensor had acceptable and better validity compared to the on-bench calibration, especially for the swing phase of gait.

Effects of Functional Electrical Stimulation on Gait Characteristics in Healthy Individuals: A Systematic Review

BACKGROUND

This systematic review aimed to provide a comprehensive overview of the effects of functional electrical stimulation (FES) on gait characteristics in healthy individuals.

METHODS

Six electronic databases (PubMed, Embase, Epistemonikos, PEDro, COCHRANE Library, and Scopus) were searched for studies evaluating the effects of FES on spatiotemporal, kinematic, and kinetic gait parameters in healthy individuals. Two examiners evaluated the eligibility and quality of the included studies using the PEDro scale.

RESULTS

A total of 15 studies met the inclusion criteria. The findings from the literature reveal that FES can be used to modify lower-limb joint kinematics, i.e., to increase or reduce the range of motion of the hip, knee, and ankle joints. In addition, FES can be used to alter kinetics parameters, including ground reaction forces, center of pressure trajectory, or knee joint reaction force. As a consequence of these kinetics and kinematics changes, FES can lead to changes in spatiotemporal gait parameters, such as gait speed, step cadence, and stance duration.

CONCLUSIONS

The findings of this review improve our understanding of the effects of FES on gait biomechanics in healthy individuals and highlight the potential of this technology as a training or assistive solution for improving gait performance in this population.

Trip-Related Fall Risk Prediction Based on Gait Pattern in Healthy Older Adults: A Machine-Learning Approach

Trip perturbations are proposed to be a leading cause of falls in older adults. To prevent trip-falls, trip-related fall risk should be assessed and subsequent task-specific interventions improving recovery skills from forward balance loss should be provided to the individuals at risk of trip-fall. Therefore, this study aimed to develop trip-related fall risk prediction models from one's regular gait pattern using machine-learning approaches. A total of 298 older adults (≥60 years) who experienced a novel obstacle-induced trip perturbation in the laboratory were included in this study. Their trip outcomes were classified into three classes: no-falls (n = 192), falls with lowering strategy (L-fall, n = 84), and falls with elevating strategy (E-fall, n = 22). A total of 40 gait characteristics, which could potentially affect trip outcomes, were calculated in the regular walking trial before the trip trial. The top 50% of features (n = 20) were selected to train the prediction models using a relief-based feature selection algorithm, and an ensemble classification model was selected and trained with different numbers of features (1-20). A ten-times five-fold stratified method was utilized for cross-validation. Our results suggested that the trained models with different feature numbers showed an overall accuracy between 67% and 89% at the default cutoff and between 70% and 94% at the optimal cutoff. The prediction accuracy roughly increased along with the number of features. Among all the models, the one with 17 features could be considered the best model with the highest AUC of 0.96, and the model with 8 features could be considered the optimal model, which had a comparable AUC of 0.93 and fewer features. This study revealed that gait characteristics in regular walking could accurately predict the trip-related fall risk for healthy older adults, and the developed models could be a helpful assessment tool to identify the individuals at risk of trip-falls.

Identification of characteristics of foot position and angle during swing phase in fallers using principal component analysis

Identifying the characteristics of fallers is important for preventing falls because such events may reduce quality of life. It has been reported that several variables related to foot positions and angles during gait (e.g., sagittal foot angle and minimum toe clearance) differ between fallers and non-fallers. However, examining such representative discrete variables may not be sufficient to detect crucial information, which may be contained in the large portions of unanalyzed data. Therefore, we aimed to identify the comprehensive characteristics of foot position and angle during the swing phase of gait in non-fallers and fallers using principal component analysis (PCA). Thirty non-fallers and 30 fallers were recruited for this study. We performed PCA to reduce the dimensions of foot positions and angles during the swing phase and obtained principal component scores (PCSs) for each principal component vector (PCV), which were then compared between groups. The results revealed that the PCS of PCV3 in fallers was significantly larger than that in non-fallers (p = 0.003, Cohen's d = 0.80). We reconstructed waveforms of foot positions and angles during the swing phase using PCV3 and our main findings can be summarized as follows. Compared to non-fallers, fallers have a 1) low average foot position in the z-axis (i.e., height) during the initial swing phase 2) small average foot angle in the x-axis (i.e., rotation in the sagittal plane), during the initial swing phase, and 3) large variability in foot position in the y-axis (i.e., anterior/posterior position) during the initial swing phase. We can conclude that these are characteristics of gait related to fallers. Therefore, our findings may be beneficial for evaluating fall risk during gait using a device such as a shoe- or insole-embedded inertial measurement unit.

Fatigue Effect on Minimal Toe Clearance and Toe Activity during Walking

This study investigates the effects of fatigue on the process of walking in young adults using the developed clog-integrated sensor system. The developed sensor can simultaneously measure the forefoot activity (FA) and minimum toe clearance (MTC). The FA was evaluated through the change in the contact area captured by a camera using a method based on a light conductive plate. The MTC was derived from the distance between the bottom surface of the clog and ground obtained using a time of flight (TOF) sensor, and the clog posture was obtained using an acceleration sensor. The induced fatigue was achieved by walking on a treadmill at the fastest walking speed. We evaluated the FA and MTC before and after fatigue in both feet for 14 participants. The effects of fatigue manifested in either the FA or MTC of either foot when the results were evaluated by considering the participants individually, although individual variances in the effects of fatigue were observed. In the dominant foot, a significant increase in either the FA or MTC was observed in 13 of the 14 participants. The mean MTC in the dominant foot increased significantly (p = 0.038) when the results were evaluated by considering the participants as a group.

THE RELATIONSHIP BETWEEN TRUNK MUSCLE STRENGTH AND PELVIC OSCILLATION IN HEALTHY ADULTS

Purpose: Pelvis and trunk structure are body segments that are integrated with each other. Collaboration between pelvic mobility and trunk muscles plays a significant role in walking and energy consumption. The aim of this study is to investigate the relationship between trunk muscle strength and pelvic oscillations. Methods: Twenty-eight healthy individuals volunteered for the study (16 women, 12 man; mean age 24.46 ± 2.97 yrs., height 172.03 ± 9.41cm, weight 67.78 ± 16.31 kg). Gait characteristics and pelvic oscillation were measured by using wireless tri-axial accelerometer. Trunk muscle strength were evaluated with Isokinetic Dynamometer (Cybex Humac Norm Testing & Rehabilitation System, USA). The trunk extensors and flexors were tested concentrically at 60°s. Statistically, the direction and level of the relationship were examined by using Spearman Correlation Analysis. Results: Correlation analysis showed significant relationships between concentric strength of trunk flexion and anterior-posterior pelvic tilt (r=-0.419), lateral pelvic tilt (r=-0.768) and hip rotation (r=-0.382). A statistically significant relationship was not observed between concentric strength of trunk extension and anterior-posterior pelvic tilt, hip rotation (p>0.05). Conclusion: The current study reports that trunk muscle strength is associated with pelvic oscillations. Also, these results suggest that maintaining optimal levels of trunk muscle strength prepares a healthful basis for the pelvis during walking. Therefore, it contributes to the prevention of possible pathologies related to lower extremity. Although trunk muscle strength and pelvic mobility are important determinants of gait, these factors are insufficient to evaluate the whole gait cycle and energy expenditure of individuals.

Multifactorial assessment of older adults able and unable to recover balance during a laboratory-induced trip

BACKGROUND

Older adults are prone to falls, and identifying fallers and non-fallers from a set of fall-related variables is essential while establishing effective preventive programs.

AIMS

This study aimed to analyze if a set of parameters (i.e., strength, functional status, dynamic balance, gait, and obesity-related anthropometric measures) differ between older adults able and unable to recover from an induced trip.

OBJECTIVE

To analyze predictors among older adults able and unable to identify fallers and non-fallers.

METHODS

Thirty healthy old adults were tripped once during the mid-swing phase of the gait. The trip outcome was used as a criterion to assign participants to a recovery (REC; n=21; 71.2±5.7 years; 70.9±12.8 kg; 1.60±0.09 m) or a non-recovery group (NREC; n=9; 69.4±6.8 years; 85.7±11.8 kg; 1.59±0.08 m). The spatiotemporal gait parameters, functional mobility, dynamic balance, and isokinetic muscular function were measured.

RESULTS

The NREC presented larger BMI (33.6±2.7 vs. 27.5±3.4 kg.m-2; p<0.05); greater time for the initiation phase on the voluntary step execution test (197.0±27.9vs. 171.7±31.3s; p<0.05); lower plantarflexor (0.41±0.15 vs. 0.59±0.18 N.m; p<0.05), dorsiflexor (0.18±0.05 vs. 0.24±0.07 N.m; p<0.05), knee extensor (1.03±0.28 vs. 1.33±0.24 N.m; p<0.05) and knee flexor peak torques (0.50±0.15 vs. 0.64±0.13 N.m; p<0.05); and greater time up and go (8.0±0.8 vs. 7.4±0.7s).

CONCLUSIONS

The results showed that it is possible to identify fall risk components based on several fall-related parameters using a laboratory-induced trip as the outcome variable.

Anipose: A toolkit for robust markerless 3D pose estimation

Quantifying movement is critical for understanding animal behavior. Advances in computer vision now enable markerless tracking from 2D video, but most animals move in 3D. Here, we introduce Anipose, an open-source toolkit for robust markerless 3D pose estimation. Anipose is built on the 2D tracking method DeepLabCut, so users can expand their existing experimental setups to obtain accurate 3D tracking. It consists of four components: (1) a 3D calibration module, (2) filters to resolve 2D tracking errors, (3) a triangulation module that integrates temporal and spatial regularization, and (4) a pipeline to structure processing of large numbers of videos. We evaluate Anipose on a calibration board as well as mice, flies, and humans. By analyzing 3D leg kinematics tracked with Anipose, we identify a key role for joint rotation in motor control of fly walking. To help users get started with 3D tracking, we provide tutorials and documentation at http://anipose.org/.

Toe Clearance Rehabilitative Slippers for Older Adults With Fall Risk: A Randomized Controlled Trial

Introduction:

To evaluate fall-prevention rehabilitative slippers for use by self-caring, independent older adults.

Materials and Methods:

This assessor-blinded, randomized, and controlled 1-year study included 59 self-caring, independent participants (49 women) who attended day services. The mean age of participants was 84.0 ± 5.3 years. Participants were randomly selected from 8 nursing homes. We tested slippers top-weighted with a lead bead (200, 300, or 400 g). Intervention group participants walked while wearing the slippers for 10-20 min, 1-3 days/week at the day service center. Fall risk was measured using the Berg Balance Scale and the Tinetti Performance-Oriented Mobility Assessment (POMA) before and at 3-month intervals after the intervention/control phase.

Results:

After 12 months, the intervention group demonstrated significant improvement. Berg Balance and POMA compared to the control group (p < .05 p < .01, respectively). Mobility scores improved significantly for both measurements in the intervention group before and after (p < .01), but the control group had significantly lower scores.

Discussion:

Overall, falls decreased in the intervention group from 10 to 7, and control group falls increased from 9 to 16 (p = .02). No adverse events related to the intervention were reported.

Conclusions:

Rehabilitation training slippers may reduce falls in older adults.

Medical aromatherapy in geriatric syndrome

Geriatric syndromes are symptoms and signs, such as falls, incontinence, delirium, pressure ulcers, dysphagia and so on, that often threaten the independence of older adults, rather than the disease itself. Although the syndromes are very common in older people, it is difficult to treat those by modern medicine due to their complexity. To mitigate the intractable geriatric symptoms, we review the efficacy of aromatherapy, especially for dysphagia, dyspnea, cognitive dysfunction and falls in geriatric syndrome. Olfactory stimulation using a volatile black pepper oil on institutional residents improved the swallowing reflex, which is a crucial risk factor of aspiration pneumonia. Brain imaging study showed that olfactory stimulation using volatile black pepper oil activated cerebral regions of the anterior cingulate and the insular cortex, which play a role in controlling appetite and swallowing. Also, aromatherapy with volatile l-menthol decreased the sense of dyspnea and improved the efficacy of exercise therapy. The fragrance of the combination of rosemary and lemon oils in the morning, and the combination of lavender and orange oils in the night-time were reported to improve cognition and behavioural and psychological symptoms of dementia, respectively. Also, the combination of lavender and lemon balm oils was reported to be effective for irritability-related agitation in older adults. Furthermore, aromatherapy with lavender fragrance could improve both static and dynamic balance, resulting in a reduction in the number of fallers and the incidence rate in older people. Thus, aromatherapy is a promising remedy for geriatric syndrome. Geriatr Gerontol Int 2021; 21: 377-385.

A Vision-Based Approach for Sidewalk and Walkway Trip Hazards Assessment

Tripping hazards on the sidewalk cause many falls annually, and the inspection and repair of these hazards cost cities millions of dollars. Currently, there is not an efficient and cost-effective method to monitor the sidewalk to identify any possible tripping hazards. In this paper, a new portable device is proposed using an Intel RealSense D415 RGB-D camera to monitor the sidewalks, detect the hazards, and extract relevant features of the hazards. This paper first analyzes the effects of environmental factors contributing to the device’s error and compares different regression techniques to calibrate the camera. The Gaussian Process Regression models yielded the most accurate predictions with less than 0.09 mm Mean Absolute Errors (MAEs). In the second phase, a novel segmentation algorithm is proposed that combines the edge detection and region-growing techniques to detect the true tripping hazards. Different examples are provided to visualize the output results of the proposed method.

Relationship between Quadriceps Tendon Young's Modulus and Maximum Knee Flexion Angle in the Swing Phase of Gait in Patients with Severe Knee Osteoarthritis

Background and objectives: Decreased knee flexion in the swing phase of gait can be one of the causes of falls in severe knee osteoarthritis (OA). The quadriceps tendon is one of the causes of knee flexion limitation; however, it is unclear whether the stiffness of the quadriceps tendon affects the maximum knee flexion angle in the swing phase. The purpose of this study was to clarify the relationship between quadriceps tendon stiffness and maximum knee flexion angle in the swing phase of gait in patients with severe knee OA. Materials and Methods: This study was conducted from August 2018 to January 2020. Thirty patients with severe knee OA (median age 75.0 (interquartile range 67.5–76.0) years, Kellgren–Lawrence grade: 3 or 4) were evaluated. Quadriceps tendon stiffness was measured using Young’s modulus by ShearWave Elastography. The measurements were taken with the patient in the supine position with the knee bent at 60° in a relaxed state. A three-dimensional motion analysis system measured the maximum knee flexion angle in the swing phase. The measurements were taken at a self-selected gait speed. The motion analysis system also measured gait speed, step length, and cadence. Multiple regression analysis by the stepwise method was performed with maximum knee flexion angle in the swing phase as the dependent variable. Results: Multiple regression analysis identified quadriceps tendon Young’s modulus (standardized partial regression coefficients [β] = −0.410; p = 0.013) and gait speed (β = 0.433; p = 0.009) as independent variables for maximum knee flexion angle in the swing phase (adjusted coefficient of determination = 0.509; p < 0.001). Conclusions: Quadriceps tendon Young’s modulus is a predictor of the maximum knee flexion angle. Clinically, decreasing Young’s modulus may help to increase the maximum knee flexion angle in the swing phase in those with severe knee OA.

Three-curve rocker-soled shoes and gait adaptations to intermittent claudication pain: A randomised crossover trial

BACKGROUND

Intermittent claudication (IC) is a symptom of peripheral arterial disease where a cramp-like leg pain is exhibited during walking, which affects gait and limits walking distance. Specifically-designed rocker-soled shoes were purported to mechanically unload the calf musculature and increase walking distances until IC pain.

RESEARCH QUESTIONS

Do three-curve rocker-soled shoes increase walking distance and what are the biomechanical differences during pain-free walking and IC pain-induced walking, when compared with control shoes?

METHODS

Following NHS ethical approval, 31 individuals with claudication (age 69 ± 10 years, stature 1.7 ± 0.9 m, mass 83.2 ± 16.2 kg, ankle-brachial pressure index 0.55 ± 0.14) were randomised in this cross-over trial. Gait parameters whilst walking with rocker-soled shoes were compared with control shoes at three intervals of pain-free walking, at onset of IC pain (initial claudication distance) and when IC intensifies and prevents them walking any further (absolute claudication distance). Two-way repeated measures ANOVA were performed on gait variables.

RESULTS

When compared with control shoes, rocker-soled shoes reduced ankle power generation (mean 2.1 vs 1.6 W/kg, respectively; p = 0.006) and altered sagittal kinematics of the hip, knee and ankle. However, this did not translate to a significant increase in initial (138 m vs 146 m, respectively) or absolute (373 m vs 406 m, respectively) claudication distances. In response to IC pain, similar adaptations in temporal-spatial parameters and the sagittal kinematics were observed between the shoe types.

SIGNIFICANCE

The three-curved rocker shoes, in their current design, do not augment gait sufficiently to enhance walking distance, when compared with control shoes, and therefore cannot be recommended for the intermittent claudication population. Clinical Reg No. (ClinicalTrials.gov): NCT02505503.

Does negative information about aging influence older adults' physical performance and subjective age?

This study investigated the way negative stereotypes influence older adults' physical performance and how old they feel mentally and physically. Sixty-four older adults aged 65 years and older performed different physical tasks using a 3D optoelectronic system under a low or high stereotype threat condition. Self-perceptions of aging were considered as a moderator of the effects of threat. Overall, the effects of threat on physical performance were mostly not significant across tasks. However, threat condition influenced older adults' mental subjective age after they had performed the physical tests; people in the high-threat condition felt closer to their chronological age. Threat also influenced participants' physical subjective age, and this effect was moderated by self-perceptions of aging. More precisely, participants in the high-threat condition felt 7% physically older than their chronological age when they had more negative self-perceptions, while participants in the low-threat condition felt 13% younger. No differences emerged for participants who had more positive self-perceptions. The present findings suggest that performing physical tests under stereotype threat might worsen older people's subjective experience of their own aging by making them feel older.

Anthropometric, functional and foot trajectory determinants of stride length in self-reliant community-dwelling elderly persons in Talca, Chile

Abstract Objective: To analyze anthropometric, muscle performance and foot trajectory determinants of stride length (SL) during walking at a comfortable pace among self-reliant community-dwelling elderly persons in Talca, Chile. Method: A total of 63 self-reliant elderly persons participated in this observational and cross-sectional study. They were characterized by the anthropometric measures of mass, height and body mass index. Dorsiflexor muscle strength performance (DF-MS) and rate of force development were quantified. Finally, the elderly persons were asked to walk comfortably around a 40 meter elliptical circuit, using determined SL and maximum foot clearance (MaxFC) and minimum foot clearance (MFC) trajectory parameters. The SL determinants were evaluated by calculating the coefficient of determination (r2) considering a level of significance of p≤0.05. Results: The anthropometric variables demonstrated significant correlations (r>0.41) with the explanation of SL remaining incipient (r2<0.20). Muscle performance, meanwhile, was significantly correlated (r>0.52), with DF-MS standing out (r2=0.342). MaxFC represented a significant explanation for the data (r2=0.396), while the low correlation of MFC was not significant (r=0.24, r2=0.058). Conclusion: MaxFC and DF-MS are determinants of SL in self-reliant elderly Chileans. It is proposed that gait parameters could be normalized in accordance with trajectory and muscular performance.

Static balance of elderly women submitted to a physical activity program

Objective : The aim of this study was to determine the effects of a physical activity program on static balance in elderly women. Method : The sample was randomly subdivided into an experimental group (EG; n=28; 65.64±2.36 years; BMI= 27.52±3.13) and a control group (CG; n=21; 66.84±2.31 years; BMI= 27.67±2.78). The EG participated in twice-weekly 60-minute sessions of physical activity for 12 weeks, with a perceived intensity level between 3 and 5 (CR10 scale). Static balance was evaluated using a baropodometric platform. Mean postural amplitude oscillations were measured in displacement from the center of pressure (COP), left lateral (LLD), right lateral (RLD), anterior (AD) posterior (PD) and elliptical (EA) area. Results : Repeated-measures analysis of variance showed a significant decrease in EG pre and post-test oscillations (p<0.05) in the COP, AD (∆=0.59;p=0.021), PD (∆=-0.91; p=0.001) and EA (∆=1.56; p=0.044) displacement. When comparing the groups, post-test amplitude oscillations in the COP, RLD (∆%=-7.40;p=0.006), AD (∆%=-30.63; p=0.007), PD (∆%=-42.96; p<0.001) and EA (∆%=-34.41;p=0.017) of the EG were significantly lower (p<0.05) than those of the CG. There were no significant LLD alterations. Conclusion : The results confirm that static balance improved with physical exercise in EG subjects.

Cognitive processes affect the gait of subjects with Parkinson’s and Alzheimer’s disease in dual tasks

Objective To investigate the relation between gait parameters and cognitive impairments in subjects with Parkinson’s disease (PD) and Alzheimer’s disease (AD) during the performance of dual tasks. Methods This was a cross-sectional study involving 126 subjects divided into three groups: Parkinson group (n = 43), Alzheimer group (n = 38), and control group (n = 45). The subjects were evaluated using the Timed Up and Go test administered with motor and cognitive distracters. Gait analyses consisted of cadence and speed measurements, with cognitive functions being assessed by the Brief Cognitive Screening Battery and the Clock Drawing Test. Statistical procedures included mixed-design analyses of variance to observe the gait patterns between groups and tasks and the linear regression model to investigate the influence of cognitive functions in this process. A 5% significant level was adopted. Results Regarding the subjects’ speed, the data show a significant difference between group vs task interaction (p = 0.009), with worse performance of subjects with PD in motor dual task and of subjects with AD in cognitive dual task. With respect to cadence, no statistical differences was seen between group vs task interaction (p = 0.105), showing low interference of the clinical conditions on such parameter. The linear regression model showed that up to 45.79%, of the variance in gait can be explained by the interference of cognitive processes. Conclusion Dual task activities affect gait pattern in subjects with PD and AD. Differences between groups reflect peculiarities of each disease and show a direct interference of cognitive processes on complex tasks.

Sex differences in whole body gait kinematics at preferred speeds

Studies on human perception have identified pelvis and torso motion as key discriminators between male and female gaits. However, while most observers would advocate that men and women walk differently, consistent findings and explanations of sex differences in gait kinematics across modern empirical studies are rare. In the present study we evaluated sex differences in whole body gait kinematics from a large sample of subjects (55 men, 36 women) walking at self selected speeds. We analyzed the data through comparisons of discrete metrics and whole curve analyses. Results showed that in the frontal plane, women walked with greater pelvic obliquity than men, but exhibited a more stable torso and head. Women had greater transverse plane pelvis and torso rotation as well as greater arm swing. Additional sex differences were noted at the hip and ankle. These kinematic results are in line with anectdotal observations and qualitative studies. In order to understand these observations and substantiate some of the explanations previously set forth in the biomechanics literature, we also explored possible reasons for dynamic sex effects, and suggested applications that may benefit from their consideration.

Effects of isokinetic eccentric training on knee extensor and flexor torque and on gait of individuals with long term ACL reconstruction: A controlled clinical trial

This study investigated the effects of the isokinetic eccentric training (IET) on the knee extensor and flexor torque and kinematic gait parameters in individuals with ACL reconstruction. Sixteen men with ACL reconstructed (ACLr) whose torque and the gait were evaluated, before and after 12 weeks of IET, was compared to a control group (14 individuals). Student t, MANOVA and ANOVA tests were performed with 5% of significance. The training increased the isometric, concentric at 30 and 120º/s (p < .05) and eccentric at 30º/s (p < .01) extensor torque on the affected limb (AL), and eccentric at 30 and 120º/s (p < .01), on the non-affected limb (NAL). In the flexors, there was an increase on the torque: isometric, concentric at 30º/s and eccentric at 30 and 120º/s (p < .01) in AL and in eccentric at 30 (p < .05) and 120º/s (p< .01) in NAL. With respect to the angular and spatio-temporal variables gait, there was no difference between pre-and post-training in LCAr group. Compared to control group, the cycle time, in two members, was lower in LCAr group, and stride length and cadence were higher in the AL of the LCAr (p < .05). Moreover, the knee flexion-extension angles (minimum and maximum) remained lower in LCAr, pre- and post-training (p < .01). The torque gain associated with eccentric isokinetic training did not affect the kinematic parameters of gait in patients undergoing ACL reconstruction.

Relationship between foot function and medial knee joint loading in people with medial compartment knee osteoarthritis

BACKGROUND

Dynamic joint loading, particularly the external knee adduction moment (KAM), is an important surrogate measure for the medio-lateral distribution of force across the knee joint in people with knee osteoarthritis (OA). Foot motion may alter the load on the medial tibiofemoral joint and hence affect the KAM. Therefore, this study aimed to investigate the relationship between tibia, rearfoot and forefoot motion in the frontal and transverse planes and the KAM in people with medial compartment knee OA.

METHOD

Motion of the knee, tibia, rearfoot and forefoot and knee moments were evaluated in 32 patients with clinically and radiographically-confirmed OA, predominantly in the medial compartment. Pearson's correlation coefficient was used to investigate the association between peak values of tibia, rearfoot and forefoot motion in the frontal and transverse planes and 1st peak KAM, 2nd peak KAM, and the knee adduction angular impulse (KAAI).

RESULTS

Lateral tilt of the tibia was significantly associated with increased 1st peak KAM (r = 0.60, p < 0.001), 2nd peak KAM (r = 0.67, p = 0.001) and KAAI (r = 0.82, p = 0.001). Increased peak rearfoot eversion was significantly correlated with decreased 2nd peak KAM (r = 0.59, p < 0.001) and KAAI (r = 0.50, p = 0.004). Decreased rearfoot internal rotation was significantly associated with increased 2nd peak KAM (r = -0.44, p = 0.01) and KAAI (r = -0.38, p = 0.02), while decreased rearfoot internal rotation relative to the tibia was significantly associated with increased 2nd peak KAM (r = 0.43, p = 0.01). Significant negative correlations were found between peak forefoot eversion relative to the rearfoot and 2nd peak KAM (r = -0.53, p = 0.002) and KAAI (r = -0.51, p = 0.003) and between peak forefoot inversion and 2nd peak KAM (r = -0.54, p = 0.001) and KAAI (r = -0.48, p = 0.005).

CONCLUSION

Increased rearfoot eversion, rearfoot internal rotation and forefoot inversion are associated with reduced knee adduction moments during the stance phase of gait, suggesting that medial knee joint loading is reduced in people with OA who walk with greater foot pronation. These findings have implications for the design of load-modifying interventions in people with knee OA.

Lower limb biomechanics in individuals with knee osteoarthritis before and after total knee arthroplasty surgery

We investigated the biomechanical changes that occur in the lower limb following total knee arthroplasty (TKA). Lower limb joint kinematics and kinetics were evaluated in 32 patients before and 12 months following TKA and 28 age-matched controls. Analysis of variance with Bonferroni-adjusted post-hoc tests showed no significant changes in knee joint kinematics and kinetics following TKA despite significant improvements in pain and function. Significant increases in peak ankle plantarflexion and dorsiflexion moments and ankle power generation were observed which may be a compensatory response to impaired knee function to allow sufficient power generation for propulsion. Differences in knee gait parameters may arise as a result of the presence of osteoarthritis and mechanical changes associated with TKA as well as retention of the pre-surgery gait pattern.

Lower limb proprioception deficits persist following knee replacement surgery despite improvements in knee extension strength

PURPOSE

Knee pain and disability can persist following knee replacement surgery which may place patients at increased risk of falls. This study investigated the falls risk and the occurrence of falls of people with knee osteoarthritis (OA) before and at 12 months following knee replacement surgery.

METHOD

Thirty-five patients with knee OA were tested prior to undergoing knee replacement surgery and at 12 months following surgery using the short form Physiological Profile Assessment, which incorporates tests of vision, lower limb proprioception, knee extension strength, reaction time and postural sway. Physical activity, number of falls, fear of falling, pain, disability and health-related quality of life were also assessed.

RESULTS

No significant differences were found between the number of falls pre- and post-surgery (n.s.), with 48.5 and 40% reporting at least one fall in the 12 months before and following the surgery, respectively. Improvements in knee strength, reaction time and fear of falling were evident following surgery, with no improvement in lower limb proprioception. Self-reported pain, function and stiffness were significantly improved, but health-related quality of life deteriorated following the surgery.

CONCLUSION

The number of falls experienced following knee replacement surgery remained relatively high, which may be attributed to the persistence of impaired lower limb proprioception. Although knee replacement surgery improves function and alleviates pain, people who undergo this procedure may need to engage in rehabilitation following the surgery to reduce the risk of falling.

LEVEL OF EVIDENCE

Therapeutic study investigating the result of treatment on patient outcomes, Level IV.

Swing limb mechanics and minimum toe clearance in people with knee osteoarthritis

OBJECTIVE

Knee osteoarthritis (OA) has been shown to be a risk factor for falls. Reductions in foot clearance during the swing phase of walking can cause a trip and potentially lead to a fall. This study examined the swing phase mechanics of people with and without knee OA during walking.

DESIGN

Minimum toe clearance (MTC) height, joint angles at the time of MTC and the influence of the angular changes of the hip, knee and ankle of the swing leg on foot clearance using sensitivity analysis were investigated in 50 knee OA participants and 28 age-matched asymptomatic controls.

RESULTS

Although both groups had a similar MTC height (controls: 12.8±6.7 mm, knee OA: 13.4±7.0 mm), the knee OA group used a different strategy to achieve the same foot clearance, as evidenced by greater knee flexion (52.5±5.3° vs 49.4±4.8°, p=0.007), greater hip abduction (-3.6±3.3° vs -1.8±3.3°, p=0.03) and less ankle adduction (2.8±1.9° vs 4.2±2.1°, p=0.01).

CONCLUSION

MTC height was comparable between the groups, however a different swing phase mechanism was used by the knee OA. Although adequate MTC is an important component of safe locomotion, it does not appear to be impaired in people with knee OA. Other factors, such as inadequate responses to postural perturbation, may be responsible for falls in this group.

Spatiotemporal components of the 3-D gait analysis of community-dwelling middle-aged and elderly Japanese: age- and sex-related differences

AIM

To describe age- and sex-related differences in gait patterns of community-living men and women using 3-D gait analysis.

METHODS

Subjects (n=2006) aged 40-84 years participated in the National Institute for Longevity Sciences-Longitudinal Study of Aging (NILS-LSA). Spatiotemporal components, including velocity, step length, step frequency, and double support time during a gait cycle, were calculated from 3-D coordinates and vertical force data. Velocity, step length and step frequency were normalized by leg length and acceleration due to gravity, and double support time was normalized to gait cycle duration.

RESULTS

Spatiotemporal walking variables of brisk velocity and step length were significantly greater in men than in women, while comfortable velocity and comfortable and brisk step frequencies and double support times were greater in women than in men. Age-related changes were marked at 70-84 years in most spatiotemporal variables in both sexes during comfortable walking. During brisk walking, age-related changes were observed from a younger age than during comfortable walking, and there were sex-related differences.

CONCLUSION

The age-related gait alteration was obvious among those aged 70 years and older, and it accelerated markedly in women's brisk walking intensity.

Combined Effects of Bag Holding and Obstacle Avoidance on Gait Characteristics: A Kinematic Study in Healthy Young Adults

Objective

This study examined the influence of holding a bag with one hand on a walkway with an obstacle on gait characteristics.

Methods

Ten healthy male students walked 5 m on obstructed and unobstructed walkways while holding loads corresponding to 0%, 10% and 20% of their body weights. General gait parameters (gait velocity, step length, etc.), the toe-obstacle clearance and the minimum toe clearance, the hip, knee and ankle joint angles of both limbs, and take-off and landing distances were analysed.

Results

With heavier loads, the step length, velocity and landing distance decreased, and flexion angles of the knee and ankle of the support limb increased on both walkways. Clearances were maintained constantly by flexion of the ankle joint in unobstructed trials and by flexion of the hip joint in obstructed trials.

Conclusion

Even in healthy adults, gait properties remarkably change owing to holding loads that equal to 10–20% of body weight on obstructed and unobstructed walkways. Clearance between toe and an obstacle/floor are maintained by using different strategies.

Effects of postural threat on walking features of Parkinson's disease patients

This study investigated whether or not gait kinematics among healthy older individuals and Parkinson's disease (PD) patients are influenced by postural threat. Eight healthy older individuals and eight PD patients were examined while walking at self-selected velocities, under three conditions of postural threat: unconstrained floor; constrained floor (19cm wide); constrained and elevated floor (19cm wide by 10cm high). Independent of the surface conditions, due to motor disturbances caused by the PD these patients walked slower, with shorter strides, and spent more time in the double support phase and less time in the swing phase than did their matched controls. Increases in postural threat resulted in altered gait kinematics for all subjects. Specifically, stride length, stride velocity, cadence, and heel contact velocity decreased, and stride duration and double support duration increased relative to increases in postural threat. All gait alterations were the result of participants' attempts to facilitate locomotion control and maintain stability. The results of this study reveal that width and height constraints effectively perturbed the balance of all of the walking older individuals. The PD patients were able to modulate gait parameters when faced by a postural threat task.

The Effect of a 12-week Combined Exercise Intervention Program on Physical Performance and Gait Kinematics in Community-dwelling Elderly Women

This study aimed to determine if combined exercise intervention improves physical performance and gait joint-kinematics including the joint angle and dynamic range of motion (ROM) related to the risk of falling in community-dwelling elderly women. A 12-week combined exercise intervention program with extra emphasis on balance, muscle strength, and walking ability was designed to improve physical performance and gait. Twenty participants attended approximately two-hour exercise sessions twice weekly for 12 weeks. Participants underwent a physical performance battery, including static balance, sit and reach, whole body reaction time, 10 m obstacle walk, 10 m maximal walk, 30-second chair stand, to determine a physical performance score, and received quantitative gait kinematics measurements at baseline and in 12 weeks. Significant lower extremity strength improvement 13.5% (p<.001) was observed, which was accompanied by significant decreases in time of the 10 m obstacle walk (p<.05) and whole body reaction time (p<.001) in this study. However, no significant differences were seen for static balance and flexibility from baseline. For gait kinematics, in the mid-swing phase, knee and hip joint angle changed toward flexion (p<.01, p<.05, respectively). Ankle dynamic ROM significantly increased (p<.05) following exercise intervention. The plantar flexion angle of the ankle in the toe-off phase was increased significantly (p<.01). However, other gait parameters were not significantly different from baseline. These findings from the present investigation provide evidence of significant improvements in physical performance related to the risk factors of falling and safe gait strategy with a combined exercise intervention program in community-dwelling elderly women. The results suggest this exercise intervention could be an effective approach to ameliorate the risk factors for falls and to promote safer locomotion in elderly community-dwelling women.